Is there a free ASN API?

Basic ASN data is free. Every free-plan IP Geolocation API response includes the , organization, and country for an IP, with . The dedicated , which adds routes, peers, upstreams, downstreams, and WHOIS data, is available on paid plans starting from , and a free trial can be activated through support.

What data does the ASN lookup API return?

Every lookup returns the core ASN record, including the , owning organization, type, website, registration country, RIR, allocation date, status, and route counts. Using the parameter adds announced IPv4 and IPv6 prefixes, peers, upstreams, downstreams, and the raw WHOIS record. The lists every response field with its type and empty-state behavior.

What are ASN peers, upstreams, and downstreams?

They describe the three relationship types around an autonomous system. exchange traffic directly, typically settlement-free. are transit providers the network relies on to reach the wider internet. are customer networks that depend on it for internet connectivity. Together they provide a complete picture of a network's connectivity and dependencies.

How much does an ASN lookup cost?

Every successful ASN lookup costs , regardless of how many options are requested. Paid plans start at with , and there are no rate limits. Every response includes the header for transparent billing. See the for complete details.

Can I download ASN data as a database instead of calling the API?

Yes. The provides daily updated IP-range-to-ASN mappings with organization, network type, route counts, and peer counts in and formats. The contains ASN registration and ownership records, making both databases ideal for batch enrichment, air-gapped deployments, and low-latency local lookups.

Developer Docs

ASN Lookup API: The Complete Network Profile

The ASN Lookup API returns the complete network profile behind any AS number or IP address: the owning organization, its type, website, and country of registration, announced IPv4 and IPv6 route prefixes, peers, upstreams, downstreams, and the raw WHOIS record. One call answers who runs a network, what they announce, and who they connect to. Free trial available.

ip:"216.73.217.15",
asn:Object,
- as_number:"AS16509",
- organization:"Amazon.com, Inc.",
- country:"US",
- type:"HOSTING",
- domain:"amazon.com",
- date_allocated:"2000-05-04",
- asn_name:"AMAZON-02",
- allocation_status:"",
- num_of_ipv4_routes:"15692",
- num_of_ipv6_routes:"5749",
- rir:"ARIN",
- routes:Array[21441],
  - routes[0]:"52.46.9.0/24",
  - routes[1]:"173.195.230.0/24",
  - routes[2]:"2600:9000:22c3::/48",
  - routes[3]:"3.172.81.0/24",
  - routes[4]:"2600:9000:2467::/48",
  - routes[5]:"2600:f0f0:8170::/48",
  - routes[6]:"3.172.35.0/24",
  - routes[7]:"13.32.240.0/24",
  - routes[8]:"2a05:d035:4080::/46",
  - routes[9]:"64.226.232.0/21",
  - ... and 21431 more
- downstreams:Array[117],
  - downstreams[0]:Object,
    - as_number:"AS54920",
    - description:"Phaedon Acquisition, Inc.",
    - country:"US",
  - downstreams[1]:Object,
    - as_number:"AS139216",
    - description:"Htroy Network Research Limited",
    - country:"CN",
  - downstreams[2]:Object,
    - as_number:"AS214160",
    - description:"Shreejal Maharjan",
    - country:"GB",
  - downstreams[3]:Object,
    - as_number:"AS213151",
    - description:"Christian Elsen",
    - country:"DE",
  - downstreams[4]:Object,
    - as_number:"AS401106",
    - description:"Techies365",
    - country:"US",
  - downstreams[5]:Object,
    - as_number:"AS153661",
    - description:"EVERLIGHT RADIOLOGY LIMITED",
    - country:"AU",
  - downstreams[6]:Object,
    - as_number:"AS36262",
    - description:"HashTable, Inc.",
    - country:"US",
  - downstreams[7]:Object,
    - as_number:"AS401041",
    - description:"Axis Security",
    - country:"US",
  - downstreams[8]:Object,
    - as_number:"AS401181",
    - description:"Cordial",
    - country:"US",
  - downstreams[9]:Object,
    - as_number:"AS61162",
    - description:"Klarna Bank AB",
    - country:"SE",
  - ... and 107 more
- upstreams:Array[189],
  - upstreams[0]:Object,
    - as_number:"AS12552",
    - description:"GlobalConnect AB",
    - country:"SE",
  - upstreams[1]:Object,
    - as_number:"AS5511",
    - description:"Orange S.A.",
    - country:"FR",
  - upstreams[2]:Object,
    - as_number:"AS6762",
    - description:"TELECOM ITALIA SPARKLE S.p.A.",
    - country:"IT",
  - upstreams[3]:Object,
    - as_number:"AS39249",
    - description:"Netassist International EOOD",
    - country:"BG",
  - upstreams[4]:Object,
    - as_number:"AS29695",
    - description:"Lyse Tele AS",
    - country:"NO",
  - upstreams[5]:Object,
    - as_number:"AS37273",
    - description:"Bandwidth and Cloud Services Group Ltd",
    - country:"UG",
  - upstreams[6]:Object,
    - as_number:"AS286",
    - description:"GTT Communications Inc.",
    - country:"US",
  - upstreams[7]:Object,
    - as_number:"AS15943",
    - description:"wilhelm.tel GmbH",
    - country:"DE",
  - upstreams[8]:Object,
    - as_number:"AS4230",
    - description:"CLARO S.A.",
    - country:"BR",
  - upstreams[9]:Object,
    - as_number:"AS31500",
    - description:"Global Network Management Inc",
    - country:"AG",
  - ... and 179 more
- peers:Array[859],
  - peers[0]:Object,
    - as_number:"AS28792",
    - description:"Public Internet Ltd",
    - country:"GB",
  - peers[1]:Object,
    - as_number:"AS40994",
    - description:"Hohl IT e.U.",
    - country:"AT",
  - peers[2]:Object,
    - as_number:"AS37273",
    - description:"Bandwidth and Cloud Services Group Ltd",
    - country:"UG",
  - peers[3]:Object,
    - as_number:"AS38880",
    - description:"Micron21 Datacentre Pty Ltd",
    - country:"AU",
  - peers[4]:Object,
    - as_number:"AS401181",
    - description:"Cordial",
    - country:"US",
  - peers[5]:Object,
    - as_number:"AS24953",
    - description:"NETPLANET GmbH",
    - country:"AT",
  - peers[6]:Object,
    - as_number:"AS25048",
    - description:"DSNET Ltd",
    - country:"GB",
  - peers[7]:Object,
    - as_number:"AS47697",
    - description:"BIX.BG Ltd.",
    - country:"BG",
  - peers[8]:Object,
    - as_number:"AS6079",
    - description:"RCN",
    - country:"US",
  - peers[9]:Object,
    - as_number:"AS22548",
    - description:"Núcleo de Inf. e Coord. do Ponto BR NIC.BR",
    - country:"BR",
  - ... and 849 more
- whois_response:" # # ARIN WHOIS data and services are subject to the Terms of Use # available at: https://www.arin.n...",

Active ASNs: 131K+
Announced IPv4 routes: 1.3M+
Announced IPv6 prefixes: 298.7K+
Network organizations: 93.4K+

Live Response

One call, the whole
network profile

One request with include=peers,downstreams, upstreams,routes,whois_response returns everything this page describes. The response below is a real, current output for AS12 (New York University).

Full API Docs

Request

curl "https://api.ipgeolocation.io/v3/asn?apiKey=<API_KEY>&asn=12&include=peers,downstreams,upstreams,routes,whois_response"

Response Preview

1{
2  "asn": {
3    "as_number": "AS12",
4    "organization": "New York University",
5    "country": "US",
6    "type": "EDUCATION",
7    "domain": "nyu.edu",
8    "date_allocated": "1984-07-05",
9    "asn_name": "NYU-DOMAIN",
10    "allocation_status": "",
11    "num_of_ipv4_routes": 12,
12    "num_of_ipv6_routes": 1,
13    "rir": "ARIN",
14
15    "routes": [
16      "192.76.177.0/24",
17      "216.165.96.0/20",
18      "2607:f600::/32",
19      "... 10 more routes"
20    ],
21
22    "downstreams": [
23      {
24        "as_number": "AS394666",
25        "description": "NYU Langone Health",
26        "country": "US"
27      }
28    ],
29
30    "upstreams": [
31      {
32        "as_number": "AS3269",
33        "description": "Telecom Italia S.p.A.",
34        "country": "IT"
35      },
36      {
37        "as_number": "AS8220",
38        "description": "COLT Technology Services Group Limited",
39        "country": "GB"
40      },
41      {
42        "as_number": "AS286",
43        "description": "GTT Communications Inc.",
44        "country": "US"
45      },
46      "... 5 more upstreams"
47    ],
48
49    "peers": [
50      {
51        "as_number": "AS3269",
52        "description": "Telecom Italia S.p.A.",
53        "country": "IT"
54      },
55      {
56        "as_number": "AS8220",
57        "description": "COLT Technology Services Group Limited",
58        "country": "GB"
59      },
60      {
61        "as_number": "AS394666",
62        "description": "NYU Langone Health",
63        "country": "US"
64      },
65      "... 8 more peers"
66    ],
67
68    "whois_response": "#
69# ARIN WHOIS data and services 
70are subject to the Terms of Use
71# available at: 
72
73https://www.arin.net/resources/registry/whois/tou/
74..."
75  }
76}

What API Offers

What You Get in Every ASN Lookup

Every ASN lookup returns the full identity of a network: who owns it, what type it is, where it is registered, what it announces, and who it connects to.

Upstream Module

The upstream providers of a target AS organization are the networks that supply its internet connectivity and routing. Knowing the transit providers of an ASN helps in understanding how traffic enters the network and which providers it relies on for connectivity. Understanding upstream relationships helps in making improved backup strategies if an upstream provider goes down or experiences difficulties.

Full API Docs

Response Preview

1{
2  "asn": {
3    "as_number": "AS1",
4    "organization": "Level 3 Parent, LLC",
5    "country": "US",
6    "...":"..."
7    "upstreams": [
8      {
9        "as_number": "AS7046",
10        "description": "Verizon Business",
11        "country": "US"
12      },
13      {
14        "as_number": "AS51925",
15        "description": "NUVEI BULGARIA EOOD",
16        "country": "BG"
17      },
18      "...":"..."
19    ]
20  }
21}

Downstream Module

Downstream organizations are the networks or customers that receive internet access from a given ASN. Obtain the list of downstream ASNs of a primary ASN to understand the network's customer base and how it distributes its internet access. This information is useful for understanding the influence and reach of a network. It is also helpful in security operations, where tracking a suspicious IP through its downstream path can assist in identifying the origin of a threat.

Full API Docs

Response Preview

1{
2  "asn": {
3    "as_number": "AS1",
4    "organization": "Level 3 Parent, LLC",
5    "country": "US",
6    "...":"..."
7    "downstreams": [
8      {
9        "as_number": "AS25139",
10        "description": "TVCABO - Comunicacoes Multimedia, Lda",
11        "country": "MZ"
12      }
13    ]
14  }
15}

Routes Module

The information returned by ASN Lookup API includes extensive details of the IPv4 and IPv6 routes controlled by a given Autonomous System. These routes represent the IP prefixes announced by the ASN to the global internet routing table. A large number of routes shows that network infrastructure is complex and has regional or global influence. Network engineers, CDNs and cyber security experts use this information for different purposes such as route filtering, threat intelligence correlation, and traffic engineering.

Full API Docs

Response Preview

1{
2  "asn": {
3    "as_number": "AS1",
4    "organization": "Level 3 Parent, LLC",
5    "country": "US",
6    ...
7    "routes": [
8      "63.215.98.24/29",
9      "8.45.82.48/29",
10      "8.13.224.128/27",
11      ...
12    ]
13  }
14}

Peers Module

One of the core features provided by the IP and ASN information API is the listing of network peers. Peers are AS organizations that connect directly to exchange traffic without intermediaries. Peering details of any network give insight into its connectivity strength and efficiency. This information is crucial for network operators, content delivery networks (CDNs), and cybersecurity teams. Analyzing the peering relationships of specific AS organizations helps determine the quality of routing paths and optimize latency-sensitive services. A network that peers with multiple global ISPs generally offers fast and reliable access across different regions.

Full API Docs

Response Preview

1{
2  "asn": {
3    "as_number": "AS1",
4    "organization": "Level 3 Parent, LLC",
5    "country": "US",
6    "...":"..."
7    "peers": [
8      {
9        "as_number": "AS25139",
10        "description": "TVCABO - Comunicacoes Multimedia, Lda",
11        "country": "MZ"
12      },
13      {
14        "as_number": "AS7046",
15        "description": "Verizon Business",
16        "country": "US"
17      },
18      "...":"..."
19    ]
20  }
21}

WHOIS Module

The WHOIS response in the ASN API provides essential registration details about the Autonomous System, including the AS number, name, allocation status, registration and update dates, and the organization responsible for managing the network. This data is useful for network administrators and security teams when communicating with network operators regarding issues. It is available in the WHOIS response field of the API.

Full API Docs

Response Preview

1{
2  "asn": {
3    "as_number": "AS1",
4    "organization": "Level 3 Parent, LLC",
5    "country": "US",
6    "type": "BUSINESS",
7    "domain": "level3.com",
8    "date_allocated": "2001-09-20",
9    "asn_name": "LVLT-1",
10    "...":"..."
11    "whois_response": "\n\n\nASNumber:       1\nASName:         LVLT-1\nASHandle:       AS1\nRegDate:        2001-09-20\nUpdated:        2024-06-18 ..."
12  }
13}

IP to ASN lookup, and ASN to IP ranges

Pass ip= and the API resolves any IPv4 or IPv6 address to its origin AS, then returns the same full profile. Pass asn= and it works the other way: the AS number expands into its announced IPv4 and IPv6 ranges. Both directions cost one credit.

Response Preview

1{
2  "ip": "8.8.8.8",
3  "asn": {
4    "as_number": "AS15169",
5    "organization": "Google LLC",
6    "country": "US",
7    "type": "BUSINESS",
8    "domain": "google.com",
9    "date_allocated": "2000-03-30",
10    "asn_name": "GOOGLE",
11    "allocation_status": "assigned",
12    "num_of_ipv4_routes": 1066,
13    "num_of_ipv6_routes": 157,
14    "rir": "ARIN",
15
16    "routes": [
17      "108.177.103.0/24",
18      "192.178.131.0/24",
19      "34.190.176.0/21",
20      "... 1220 more routes"
21    ],
22
23    "downstreams": [
24      {
25        "as_number": "AS36040",
26        "description": "Google Fiber Inc.",
27        "country": "US"
28      },
29      {
30        "as_number": "AS139190",
31        "description": "Google Asia Pacific",
32        "country": "SG"
33      },
34      {
35        "as_number": "AS16550",
36        "description": "Google Ireland Limited",
37        "country": "IE"
38      },
39      "... + 17 more downstreams"
40    ],
41
42    "upstreams": [
43      {
44        "as_number": "AS3356",
45        "description": "Level 3 Parent, LLC",
46        "country": "US"
47      },
48      {
49        "as_number": "AS1299",
50        "description": "Arelion",
51        "country": "SE"
52      },
53      {
54        "as_number": "AS2914",
55        "description": "NTT Communications",
56        "country": "JP"
57      },
58      "... + 137 more upstreams"
59    ],
60
61    "peers": [
62      {
63        "as_number": "AS3356",
64        "description": "Level 3 Parent, LLC",
65        "country": "US"
66      },
67      {
68        "as_number": "AS1299",
69        "description": "Arelion",
70        "country": "SE"
71      },
72      {
73        "as_number": "AS6939",
74        "description": "Hurricane Electric",
75        "country": "US"
76      },
77      "... + 715 more peers"
78    ],
79
80    "whois_response": "ASNumber:       15169
81ASName:         GOOGLE
82OrgName:        Google LLC
83..."
84  }
85}

Response Data

What the ASN API returns

Six groups of data in every full lookup. Each card summarizes one; the docs carry the field-by-field reference for all of them.

UPSTREAMS

DOWNSTREAMS

WHOIS record

Hover to expand

2# ARIN WHOIS data and services are subject to the Terms of Use

3# available at: https://www.arin.net/resources/registry/whois/tou/

5# If you see inaccuracies in the results, please report at

6# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/

10ASNumber: 15169

11ASName: GOOGLE

12ASHandle: AS15169

13RegDate: 2000-03-30

14Updated: 2012-02-24

15Ref: https://rdap.arin.net/registry/autnum/15169

16OrgName: Google LLC

17OrgId: GOGL

18Address: 1600 Amphitheatre Parkway

19City: Mountain View

20StateProv: CA

21PostalCode: 94043

22Country: US

23RegDate: 2000-03-30

24Updated: 2019-10-31

25Comment: Please note that the recommended way to file abuse complaints are located in the following links.

26Comment:

27Comment: To report abuse and illegal activity: https://www.google.com/contact/

28Comment:

29Comment: For legal requests: http://support.google.com/legal

30Comment:

31Comment: Regards,

32Comment: The Google Team

33Ref: https://rdap.arin.net/registry/entity/GOGL

34OrgAbuseHandle: ABUSE5250-ARIN

35OrgAbuseName: Abuse

36OrgAbusePhone: +1-650-253-0000

37OrgAbuseEmail: network-abuse@google.com

38OrgAbuseRef: https://rdap.arin.net/registry/entity/ABUSE5250-ARIN

39OrgTechHandle: ZG39-ARIN

40OrgTechName: Google LLC

41OrgTechPhone: +1-650-253-0000

42OrgTechEmail: arin-contact@google.com

43OrgTechRef: https://rdap.arin.net/registry/entity/ZG39-ARIN

44RTechHandle: ZG39-ARIN

45RTechName: Google LLC

46RTechPhone: +1-650-253-0000

47RTechEmail: arin-contact@google.com

48RTechRef: https://rdap.arin.net/registry/entity/ZG39-ARIN

49#

50# ARIN WHOIS data and services are subject to the Terms of Use

51# available at: https://www.arin.net/resources/registry/whois/tou/

52#

53# If you see inaccuracies in the results, please report at

54# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/

55#

57#

Core ASN record

The AS number, owning organization, ASN type (ISP, hosting, business, education, or government), website, country of registration, RIR, allocation date, and current allocation status. Enough to answer 'who runs this network' from a single object.

Route prefixes

Every IPv4 and IPv6 prefix the AS announces to the global routing table, plus per-family route counts. Use it for allowlists, blocklists, route filtering, and footprint analysis.

Peers

The networks this AS exchanges traffic with directly, each with its AS number, name, and country. Peering breadth is the fastest read on how well-connected a network is.

Downstreams

The customer networks that receive connectivity through this AS. Downstream chains let security teams trace where a suspicious network actually gets its transit.

Upstreams

The transit providers this AS relies on to reach the rest of the internet. Upstream lists reveal dependency: one upstream is a single point of failure, five is resilience.

WHOIS record

The raw registry text for the ASN: registrant organization, handles, registration and update dates, and points of contact. No second WHOIS query needed.

Full field reference in the ASN API Docs

Data Foundation

How the
ASN data stays current

The ASN dataset is rebuilt every day from two source families: global BGP routing feeds, which show what every AS actually announces and who it connects through, and the five regional internet registries which hold the registration record

Collect

Routing table snapshots and live update streams from BGP vantage points worldwide, alongside delegation files and WHOIS records from all five RIRs.

Clean

Deduplicate announcements across vantage points, drop bogon and reserved space, filter route leaks and flap noise, and expire prefixes that leave the routing table.

Extract Routes

Map every announced IPv4 and IPv6 prefix to its origin AS, producing the per-ASN route lists and counts the API returns.

Map Relationships

Analyze observed AS paths to classify each adjacency as customer, provider, or peer. That classification is what the API serves as upstreams, downstreams, and peers.

Enrich and Normalize

Registry records merge into the routing view and organization names are normalized. Each ASN then carries its type and registration details.

Publish

The rebuilt dataset ships daily to the ASN API and the downloadable databases, and the build date renders in the stat band above.

The API itself runs on global edge infrastructure with a 99.99% uptime SLA; current latency is public on the status page

Request Demo

Compare

What most ASN lookups leave out

ASN data comes in four packages: free lookup tools, lite databases, geolocation APIs with an ASN field, and dedicated ASN APIs. They answer different questions, and most stop well before the relationship data.

What to check	Free lookup tools	Lite ASN databases	Geolocation APIs with an ASN field	IPGeolocation ASN API
Lookup directions	IP or ASN, in a browser, rate-capped	IP ranges to ASN only	IP only	IP and ASN, by API
Core record	AS number, name, organization	2 to 5 fields per row	AS number and organization	Organization, type, website, country, RIR, allocation date, status
Route prefixes	Rare	Not per ASN	Typically absent	IPv4 and IPv6, with counts
Peers, upstreams, downstreams	Not returned	Not included	Not included	All three, in one response
WHOIS record	Separate tool	Not included	Not included	Raw registry text in the response
Update cadence	Rarely stated	Monthly is common	Varies by plan	Daily, build date shown

If the question is "who is this network and who moves its traffic," only the last column answers it.

The Same Data Other Shapes

Resolving addresses at scale? The IP to ASN Database ships the same mapping as a daily-updated MMDB or CSV for local, zero-latency lookups. For an IP's location, currency, timezone alongside basic ASN data, use the IP Geolocation API.

IP to ASN Database

The full IP-to-ASN mapping as daily-updated MMDB and CSV files for local, zero-latency resolution at any volume.

View IP to ASN Database

ASN WHOIS Database

Registration and ownership records for every allocated ASN, built for compliance research and bulk attribution work.

View ASN WHOIS Database

IP Geolocation API

Location, currency, timezone, company, and basic ASN data for any IP in one combined response.

View IP Geolocation API

Tier Overview

Explore the Geo Advance Database Tier

Explore every Geo Advance database in one place, including geolocation, ASN, company, and WHOIS data, then pick individual datasets or build a custom mix. Compare bundles that pair Geo Advance with Geo Standard or Security Pro. Includes sample data, schemas, update cadence, and field lists for every database in the tier.

View Geo Advance Tier

Daily & weekly updates

Sub-millisecond local lookups

Locally Hosted Data

MMDB, CSV, and JSON formats

No per-query costs or rate limits

Use Cases

Cybersecurity and Threat Detection

ASN data helps security teams identify the source of malicious network activity with greater precision. By continuously monitoring ASN-related patterns, security professionals can detect anomalies more quickly and mitigate emerging threats before they escalate. Leveraging this intelligence allows them to make smarter, data-driven decisions, and proactively defend their infrastructure.

Network Performance and Routing Optimization

Network engineers can analyze ASN data to optimize routing paths and reduce latency. An understanding of peering relationships between ASNs helps them identify the optimal path for data packets, ensuring efficient data delivery and an improved user experience. Additionally, by utilizing peering information, ISPs can bypass transit providers and reduce operational costs.

Business and Market Analysis

By understanding where internet connections are coming from (geolocation) and which network they belong to (ASN information), businesses can get a much clearer and more accurate picture of where their customers are, which internet companies or organizations they use, and how people in different areas are using their services. This deeper understanding helps them build more effective marketing strategies, make customer interactions feel more personal, and focus on reaching the right people to get the best results.

Fraud Detection and Prevention

Financial institutions and e-commerce platforms can use ASN finder tools to identify suspicious transactions and activities originating from high-risk ASNs. By pinpointing these potential threats early, organizations can make smarter decisions, such as implementing additional verification steps, monitoring high-risk traffic more closely, and proactively preventing fraudulent activities. This not only strengthens security measures but also builds greater trust with customers by safeguarding their financial and personal information.

Network Infrastructure Planning

By observing ASN peering relationships, upstream providers, and downstream organizations, ISPs can strategically plan which ASes they should connect to in order to make optimal decisions for their network infrastructure. Through careful analysis of traffic patterns, capacity demands, and geographic distribution, ISPs can design a more efficient, resilient, and cost-effective network. This proactive approach improves overall network performance, reduces latency, and minimizes dependency on costly transit providers, ensuring better service quality for end users.

ASN Lookup API FAQs

Basic ASN data is free. Every free-plan IP Geolocation API response includes the AS number , organization, and country for an IP, with 1,000 credits per day . The dedicated ASN API , which adds routes, peers, upstreams, downstreams, and WHOIS data, is available on paid plans starting from $19/month , and a free trial can be activated through support.

Yes. Pass ip= with any IPv4 or IPv6 address and the API resolves it to the origin AS before returning the complete ASN profile, including routes and relationships when requested. Passing asn= queries a network directly. If both are provided, asn= takes priority. If neither is supplied, the API resolves the caller's IP address.

The ASN dataset is updated daily . It is rebuilt every day using BGP routing feeds and data from the five Regional Internet Registries (RIRs), ensuring new allocations, route changes, and relationship updates are reflected in the next build. The same update schedule also applies to the IP to ASN Database.

Yes. The ASN API fully supports IPv6. IP-to-ASN lookups accept IPv6 addresses, and every ASN profile includes announced IPv6 prefixes and IPv6 route counts alongside IPv4 information. IPv6 lookups do not incur additional charges and are available on the same plans as IPv4.

Every lookup returns the core ASN record, including the AS number , owning organization, type, website, registration country, RIR, allocation date, status, and route counts. Using the include parameter adds announced IPv4 and IPv6 prefixes, peers, upstreams, downstreams, and the raw WHOIS record. The ASN API documentation lists every response field with its type and empty-state behavior.

They describe the three relationship types around an autonomous system. Peers exchange traffic directly, typically settlement-free. Upstreams are transit providers the network relies on to reach the wider internet. Downstreams are customer networks that depend on it for internet connectivity. Together they provide a complete picture of a network's connectivity and dependencies.

Every successful ASN lookup costs 1 credit , regardless of how many include options are requested. Paid plans start at $19/month with 150,000 credits , and there are no rate limits. Every response includes the X-Credits-Charged header for transparent billing. See the Credits Usage Guide for complete details.

Yes. The IP to ASN Database provides daily updated IP-range-to-ASN mappings with organization, network type, route counts, and peer counts in MMDB and CSV formats. The ASN WHOIS Database contains ASN registration and ownership records, making both databases ideal for batch enrichment, air-gapped deployments, and low-latency local lookups.

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ASN Lookup API: The Complete Network Profile

One call, the wholenetwork profile

What You Get in Every ASN Lookup

Upstream Module

Downstream Module

Routes Module

Peers Module

WHOIS Module

IP to ASN lookup, and ASN to IP ranges

What the ASN API returns

How the ASN data stays current

Collect

Clean

Extract Routes

Map Relationships

Enrich and Normalize

Publish

What most ASN lookups leave out

The Same Data Other Shapes

IP to ASN Database

ASN WHOIS Database

IP Geolocation API

Explore the Geo Advance Database Tier

Use Cases

Cybersecurity and Threat Detection

Network Performance and Routing Optimization

Business and Market Analysis

Fraud Detection and Prevention

Network Infrastructure Planning

ASN Lookup API FAQs

Ready to get started? Add ASN Lookup API to your stack today

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One call, the whole
network profile

How the
ASN data stays current